如何使用void方法递归反转链表？

Im having trouble inverting a linked list with a void method. Im only alowed to use two pointer nodes (p,q). I´ve found several methods but not a void one. I need the root list to be modifed itself(that´s why it has to be a void method). The method has to be recursive(I know base definitions are different in void methods). Here's what i've done so far(not much). Im having trouble inverting a linked list with